What Happens Inside the Brain During a Workout?

If you think a minute goes by really fast, you’ve never been on a treadmill.

The first minutes of a workout, be it cardio or strength training, are usually the toughest to cope with, as the brain perceives this moment as a stressful experience and starts releasing a series of chemicals that send the body into the fight or flight mode. First it’s the BDNF or brain-derived neurotrophic factor, a protein whose role is to protect the organism from stress and to “reset” the brain. This neurotransmitter can enhance brain health and memory and makes us feel at ease and see things clearer after a workout.

After the first few minutes, the body starts releasing endorphins so as to minimize the discomfort produced by exercising. Endorphins are known to fight stress and to induce a feeling of euphoria, being able to block the sensation of pain and helping us push harder and workout for longer, without feeling exhausted during the exercise session.

Besides these effects, endorphins also reduce the appetite, improve the immune function and act like natural mood enhancers, reducing the risk of depression, contributing to a better memory and focus and improving the self-esteem level.

According to scientists at the Duke University, exercising for 40 minutes a day, 3-5 days a week, at moderate intensity, can stimulate and increase the release of these chemicals, contributing to a better mood and cognitive performance.

Still, this isn’t the only way the brain benefits from a workout session. Exercise also increases the heart rate and makes the heart pump more blood and deliver more oxygen to brain cells. This contributes to the release of a series of hormones inside the brain and nourishes the cells in a more efficient way. As a result, new connections between cells are established and brain’s plasticity is improved. UCLA scientists have proven that exercise increases the growth factors in the brain, making it easier for new neuronal connections to develop.

How long should we exercise?

The highest levels of endorphins are released at the beginning of the workout, during the first 20 minutes. If you’re not used to exercising at higher intensities or you’re a sedentary person who spends most of their time on the couch, you might find it very difficult to manage the first 5-15 minutes, as your body will produce elevated levels of cortisol and GABA, hormones that cause stress and blunt the brain’s pleasure receptors. As a result, you’ll feel the continuous desire to stop from exercising and give your body a rest.

Your body will continue to produce these hormones even after you get used to longer workouts, but neurotransmitters related to your brain’s reward centers will block the GABAs, preventing your body from feeling stressed or tired. As a result, you’ll be able to work out for longer and the exercise session will be perceived as a rewarding and pleasant one. The key is to do your best to maintain the pace during your workouts for at least 20 minutes per day.

Still, if you want to get the most of your training sessions, you should aim for 30 minutes of exercise per day, as this reduces the risk of chronic diseases, boosts your productivity and contributes to an overall healthier and a leaner body.

Exercising for 30-60 minutes a day helps you maintain a healthy weight, and coupled with a clean diet it can promote weight loss. Yet, if you have a higher amount of weight to lose or you’re an athlete who trains for a competition, you should aim for 60-90 minutes of exercise per day.